1. Field of the Invention
The present invention is broadly concerned with new aqueous concentrates adapted for dilution to form use compositions and methods of using the diluted compositions to prevent or treat hoof diseases in animals. More particularly, the concentrates include a quaternary ammonium compound such as those selected from the group consisting of alkyl dimethyl benzyl ammonium salts, alkyl dimethyl ethyl benzyl ammonium salts, dialkyl dimethyl ammonium salts, dialkyl methyl benzyl ammonium salts, and mixtures thereof. The concentrates also include an acid and a surfactant.
2. Description of the Prior Art
Papillomatous digital dermatitis (PDD) or hairy hoof warts was first reported in 1974 and has since presented an increasing problem to dairy farms. As many as 47% of the dairy operations in the United States are affected by PDD, with the disease occurring in 40 or more states (see Digital Dermatitis on U.S. Dairy Operations, NAFMS Dairy ""96 (1997), incorporated by reference herein). The etiology of PDD is unknown, although two to five spirochetes have been identified during the course of the disease.
The lesions first appear as eroded areas, usually between the heel bulbs. Ulcerative lesions are common in the early stages of the disease and are circumscribed with a red, granular (strawberry-like) surface. More mature lesions have a gray or yellowish-brown surface with tissue proliferations which grossly resemble hair. The lesions are very painful to the infected animal and can lead to a reduction in feed intake and a daily decrease in milk production of up to 50% in the affected cow (Rehbun et al., Interdigital Papillomatosis in Dairy Cattle, JAVMA, 137(5):437-40 (1980), incorporated by reference herein).
Various treatments have been attempted in order to prevent PDD and/or to promote healing of PDD lesions. For example, parenteral antibiotics have been administered to infected cattle, but this treatment requires milk withdrawal. Antibiotics have been applied topically (e.g., via spraying) to the affected area, but this treatment can cause the milk to be contaminated by the antibiotic. Additionally, there is concern that improper use of antibiotics will result in resistance of the disease to the antibiotic, thus making the disease even more difficult to treat. Furthermore, the antibiotic solutions are typically placed in a footbath through which the cattle walk after milking. However, because the antibiotic solutions are clear like water, there is a risk that the cattle will drink the solution, thus resulting in rumen damage.
Bandaging hooves with a topical treatment has been reported to be relatively effective, but it can be very labor-intensive and may not be practical for herds with a high incidence of the disease. Germicidal footbaths have also been utilized to apply a treatment solution to the affected area, but these footbaths are quickly overcome by the high organic loads to which they are subjected. As a result, the treatment solution must be replaced frequently, rendering the footbath a costly and labor-intensive method of treatment. Finally, many of these prior art treatment compositions or solutions contain copper as their active ingredient. While copper can be effective at treating the disease, it is also highly toxic to aquatic life. This is of particular concern because farmers typically wash farm waste into a lagoon, where the waste can seep into the soil and contaminate groundwater.
There is a need for effective and affordable treatments for treating hoof diseases in animals. This treatment should avoid the use of antibiotics, be effective for use as a spray or in a footbath in spite of the high level of contaminants which may be introduced into the footbath during use, and provide alternatives to the current copper-containing treatment solutions or compositions.
The present invention broadly provides aqueous concentrates adapted for dilution with water to form use compositions, and methods of using these compositions to treat hoof diseases such as PDD.
In more detail, the aqueous concentrates according to the invention comprise, and preferably consist essentially of, a quaternary ammonium compound, a surfactant, and an acid. Preferred quaternary ammonium compounds include those with biocidal properties, with particularly preferred such compounds being selected from the group consisting of alkyl (preferably C8-C20, and more preferably C12-C16) dimethyl benzyl ammonium salts, alkyl (preferably C8-C20, and more preferably C12-C18) dimethyl ethyl benzyl ammonium salts, dialkyl (preferably each alkyl group is individually selected from the group consisting of C8-C20 alkyl groups, and more preferably C8-C10 alkyl groups) dimethyl ammonium salts, dialkyl (preferably each alkyl group is individually selected from the group consisting of C8-C20 alkyl groups, and more preferably C12-C18 alkyl groups) methyl benzyl ammonium salts, and mixtures thereof. The most preferred quaternary ammonium compounds are selected from the group consisting of N-alkyl dimethyl benzyl ammonium chloride, octyl decyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, and mixtures thereof.
The quaternary ammonium compound should be present in the concentrate at a level of from about 1-30% by weight, preferably from about 5-20% by weight, and more preferably from about 5-15% by weight, based upon the total weight of the concentrate taken as 100% by weight.
The surfactant should be present in the concentrate at a level of from about 1-30% by weight, preferably from about 1-20% by weight, and more preferably from about 5-20% by weight, based upon the total weight of the concentrate taken as 100% by weight. The surfactant is preferably a surfactant selected from the group consisting of amphoteric surfactants, nonionic surfactants, and mixtures thereof. Even more preferably, the concentrate includes at least one amphoteric surfactant and at least one nonionic surfactant. Preferred amphoteric surfactants include imidazolines and betaines. Preferred nonionic surfactants include alkyl (preferably C8-C9) phenol or alcohol ethoxylates, ethylene oxide propylene oxide adducts, and mixtures thereof. The alcohol ethoxylates are preferably C9-C13 linear primary alcohol ethoxylates and preferably comprise an average of from about 5-9 moles of ethylene oxide per mole of alcohol. One such surfactant is commercialized under the name NEODOL 1-7 (C11 alcohol ethoxylate with 7 moles of ethylene oxide per mole of alcohol; available from Shell). The surfactant is particularly useful for providing stability to the composition, enhancing the detergency of the composition, and aiding in wetting the area to be treated.
The acid is preferably present in sufficient quantities to adjust the pH of the composition to less than about 4, preferably less than about 3, and more preferably less than about 2. This generally results in there being from about 0.5-15% by weight, preferably from about 0.5-10% by weight, and more preferably from about 1.0-10% by weight of the acid present in the concentrate. Preferred acids include glycolic acid, citric acid, lactic acid, phosphoric acid, hydrochloric acid, sulfuric acid, acetic acid, formic acid, nitric acid, and mixtures thereof.
It will be appreciated that optional ingredients can also be incorporated into the concentrates to alter certain properties thereof. For example, coloring agents (e.g., red or yellow dyes) can be added so that the use compositions formed from the concentrates can be visually observed when applied to the affected areas of the animal. Furthermore, the concentrates can include exfoliants (e.g., glycolic acid, salicylic acid), buffering agents (e.g., citric acid), and/or thickening or viscosity building agents (e.g., polyacrylic acids).
The concentrates are adapted for dilution with water to form aqueous use compositions, with the amount of the preferred dilutions depending upon the desired end use. That is, topical spray use compositions are preferably formed by mixing from about 0.5-25% by volume, and preferably from about 5-20% by volume of the concentrate with water to yield the use composition. Use compositions to be applied under a bandage wrap are preferably formed by mixing from about 0.5-25% by volume, and preferably from about 5-20% by volume of the concentrate with water to yield the use composition. Finally, use compositions to be used in a footbath are preferably formed by mixing from about 0.5-25% by volume, and preferably from about 0.5-20% by volume of the concentrate with water to yield the use composition.
Thus, use compositions formed from the inventive concentrates can be applied to the affected area by wiping or spraying the composition on the area. Alternately, a cloth or a piece of cotton or other absorbent material can be soaked in the composition and held against the lesions with a bandage wrap. When applied as a topical spray, the composition is preferably applied at least about 3 times per week. When applied under a bandage wrap, the wrap should remain on the affected area for at least about 24 hours. Finally, the compositions can be placed in a footbath, allowing the cattle to walk through the bath as they exit the milking facility. It will be appreciated that this allows for the composition to be used as a treatment for an infected hoof as well as a preventive measure to keep a healthy hoof free of disease.